A conventional strap pipe wrench is disclosed in PCT Patent No. WO2009/004201 and contains a handle, a strap, a connecting mechanism moving relative to the handle, and a movable member for moving the connecting mechanism. The handle includes a support block for driving a cylindrical object to move, and wherein the connecting mechanism moves between a first position and a second position. The strap is released at the first position, and the strap is tighten at the second position. The movable member includes a locking element for fixing the connecting mechanism at the first position relative to the handle. The strap pipe wrench further contains a driving mechanism for pushing the connecting mechanism to move toward the second position and a controlling mechanism for releasing the locking element.
However, a structure of the connecting mechanism is complicated and is produced at a high cost. Furthermore, the conventional strap pipe wrench is fixed by the controlling mechanism, and the connecting mechanism is positioned at the first position by ways of the locking element, thereafter the handle is grasped by one hand, and the strap is held and is manually operated by the other hand to adjust a length of the strap for corresponding to a diameter of the cylindrical object, thus operating the conventional strap pipe wrench troublesomely.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.